1. Field of the Invention
The present invention relates to a portable terminal, and more particularly to a hinge device of a portable terminal, which can improve structural stability while rotatably coupling one pair of housings.
2. Description of the Related Art
Generally, a portable terminal refers to an apparatus for providing users with mobile communication functions. Nowadays, a portable terminal is not only used as a simple mobile communication device, but is also used as a device for performing a hybrid function, e.g. a multimedia device for playing music files, moving picture files, etc., or a financial service device for performing retail payment, mobile banking, etc., by using a terminal.
Such a portable terminal may be classified as a bar-type portable terminal, a flip-type portable terminal, a folder-type portable terminal, or a slide type terminal according to its appearance. Slide type terminals account for the bulk of portable terminal markets together with folder-type terminals.
A bar-type terminal has a construction in which an input/output device such as a keypad and a transmitter, a display unit, and an output device such as a receiver are provided in a single housing. All elements capable of using mobile communication functions are provided within the single housing, so the bar-type terminal can be simplified. However, since it is necessary to ensure a constant distance between a transmitter and a receiver for voice communication, the bar-type terminal has a limitation in potential miniaturization.
A flip-type terminal has a construction in which all input/output devices are provided in a single housing as with a bar-type terminal, and a flip cover is pivotally attached to the housing so as to prevent fault operations from occurring by closing off an input device such as a keypad in a communication standby mode. However, the flip-type terminal has a limitation in potential miniaturization due to a problem in ensuring the distance between a transmitter and a receiver as with the bar-type terminal.
A folder-type terminal has a construction in which one pair of housings can be folded. An input device and an output device are located in each housing, so the folder-type terminal can be easily miniaturized. Further, since it is possible to easily ensure the distance between a transmitter and a receiver, it has accounted for the bulk of portable terminal markets for a long time.
A slide type terminal has a construction in which one pair of housings can be slid while facing each other. An input device, specifically, a keypad, is covered or uncovered according to sliding of the housings, so that abnormalities can be prevented and the slide type terminal can be easily miniaturized. Such slide type terminals satisfy various users' preferences.
Nowadays, as a Digital Multimedia Broadcasting (DMB) service, etc., is commercialized, a portable terminal can function as a broadcast receiver in addition to a simple communication device and a sound playback device.
However, since conventional portable terminals have been designed based on communication functions, it is inconvenient to watch broadcasting through such portable terminals. That is, a user watches broadcasting for a long time while looking at a display unit. Accordingly, in order to orient the screen display direction to the user-side in the conventional portable terminals, a user must hold the terminal. Further, various types of terminals have been proposed in order to overcome the disadvantages of such conventional portable terminals, but it is difficult to ensure the reliability of these proposed terminals because they are structurally unstable.